Sökning: "Group 14 Elements"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden Group 14 Elements.

  1. 1. Organic Heavy Group 14 Element Compounds : A Study of Their Chemical Bonding Properties Directed Towards Applications as Molecular Wires and in Synthesis

    Författare :Julius Tibbelin; Henrik Ottosson; Christoph Marschner; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Silicon; Group 14 Elements; Silenes; Conjugation; Chemical Bonding; Electronic Structure; Protecting Group Chemistry; Physical organic chemistry; Fysikalisk organisk kemi; Chemistry with specialization in Organic Chemistry; Kemi med inriktning mot organisk kemi;

    Sammanfattning : The research described herein includes synthesis, spectroscopy, and quantum chemical calculations with focus on the characteristic properties of compounds with bonds between carbon and the heavier Group 14 elements.The chapters based on the first four papers concern σ- and σ/π-conjugated compounds, although the focus of the first paper is on ring strain of bicyclo[1. LÄS MER

  2. 2. Hyperconjugation in Group 14 Organic Compounds : Design and Property Investigations

    Författare :Aleksandra Denisova; Henrik Ottosson; Thomas Müller; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; 1; 4-disilacyclohexa-2; 5-diene; aromaticity; computational chemistry; conjugation; cross-hyperconjugation; hyperconjugation; group 14 elements; organosilicon chemistry; silole;

    Sammanfattning : Nowadays π-conjugated molecules are widely used as materials for devices in organic and molecular electronics. This is due to the ability of such molecules to conduct electricity. However, π-conjugation leads to molecular rigidness and associated lower solubility, which limits possible applications. LÄS MER

  3. 3. Conjugation in Organic Group 14 Element Compounds : Design, Synthesis and Experimental Evaluation

    Författare :Rikard Emanuelsson; Henrik Ottosson; Rik Tykwinski; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; conjugation; conductance; electronic structure; Group 14 elements; hyperconjugation; molecular electronics; organosilicon chemistry; Chemistry with specialization in Organic Chemistry; Kemi med inriktning mot organisk kemi;

    Sammanfattning : This thesis focuses on the chemical concept of conjugation, i.e., electron delocalization, and the effect it has on electronic and optical properties of molecules. LÄS MER

  4. 4. Gymnasielärare - perspektiv på lärares arbete och yrkesutveckling vid millennieskiftet

    Författare :Ulf Lundström; Lisbeth Lundahl; Per-Olof Erixon; Sverker Lindblad; Umeå universitet; []
    Nyckelord :SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; teaching profession; upper secondary teachers; change; school reform; professional development; school development; frame factors; school governance; school policy; trade union; Pedgogical work; Pedagogiskt arbete;

    Sammanfattning : The aim of this thesis is to contribute to knowledge about how the work and profession of upper secondary school teachers is understood and shaped by the teachers in the beginning of the 21st century, and to relate that understanding of work and professional development to the strivings of the teachers’ trade unions and the state. With the implementation of an innovation as a starting point, the teachers’ narratives also described their work in a broader sense. LÄS MER

  5. 5. Heavy-Core Staffanes : A Computational Study of Their Fundamental Properties of Interest for Molecular Electronics

    Författare :Niclas Sandström; Henrik Ottosson; Leif Hammarström; Bo Albinsson; Uppsala universitet; []
    Nyckelord :Organic chemistry; conjugation; polarizability; Group 14 elements; cage compounds; electronic excitations; quantum chemistry; molecular electronics; Organisk kemi;

    Sammanfattning : The basic building blocks in molecular electronics often correspond to conjugated molecules. A compound class consisting of rigid rod-like staffane molecules with the heavier Group 14 elements Si, Ge, Sn and Pb at their bridgehead positions has now been investigated. LÄS MER